Baked-goods behemoth Entenmann's learned this the hard way yesterday when its social media agency sent a marketing tweet using a hashtag -- a searchable keyword or term on Twitter -- that was associated with the "not guilty" verdict in the Casey Anthony murder trial.

As the hashtag #notguilty rose among the trending topics on Twitter following the ruling, this tweet went out over the @Entenmanns feed: "Who's #notguilty about eating all the tasty treats they want?!" The tweet was later deleted after @Entenmanns followers, and others around the Twittersphere, began tweeting their disapproval of the company's insensitive use of the hashtag. The company's social media agency, Likeable Media, then sent two tweets under the @Entenmanns account to apologize.

Likeable explained in a separate statement that its staff was "leveraging the trending topics and moving so fast they neglected to see what the hashtag was related to."

To help avoid Twitter snafus such as this one, businesses of all sizes can benefit from establishing social media policies. "Do not tweet on a whim or from a mobile phone when doing so on behalf of your business," warns Jason Keath, president of Social Fresh, a social media education company. Keath says to verify that the person who is tweeting for your business is familiar with your social-media policies or has his or her updates approved by someone who is.

Here, Keath offers his top tips for using hashtags, and to ensure that your business tweets aren't harming your brand:

• Know thy hashtag. "Do not use hashtags if you are unsure what they mean," Keath says. Since hashtags are searchable, incorporating trending hashtags into tweets can drive additional traffic to your business Twitter account and in turn to your website. But not knowing what those hashtags refer to -- such as in the case of Entenmann's -- can link your brand with a subject that you may not want to be associated with.

• Develop your own hashtags. Instead of adopting hashtags for the most popular trending topics, Keath recommends creating your own hashtags to organize specific content types from your business. For instance, if you're planning a series of tweets related to the same product or service, using a hashtag can allow your followers to track all your tweets about those topics.

• Start conversations. Find ways to participate in hashtag conversations that clearly identify a relevant community, such as for a Twitter Chat. These are discussions that use a predefined hashtag to link tweets into a virtual conversation and can help your followers to chat about your products or services.

What's the biggest mistake to avoid when managing a business social media account? Let us know in the comments section below.